I don't think that Washington Sundar is a replacement for Hard dick. A spin-bowling allrounder can't replace a pace-bowling allrounder, as both of them are suitable for different occasions. For the first option, we already have Ravindra Jadeja. No matter how hard Kohli and his cronies try, it will be hard for Washington to perform at a level above that of Jadeja. The only plus point for the former is that he enjoys support from Kohli, as Jadeja is being considered as close to MS Dhoni. And I don't want to comment anything more on Rahul. He is a complete waste. I don't want to squander my time commenting on him.
An all-rounder is an all-rounder for me regardless of whether he is a spinner or a pacer. Since Pandya was out of the team they needed someone who can come in handy with bat and ball. Sunder was the correct choice at the moment. Jadeja would have been a great choice as an allrounder but I guess he might have not yet recovered from his injury. India also needs a replacement for him in the future and given the situation Sunder is a good choice.